Matchbox oven with heat sink temperature control

ABSTRACT

A matchbox oven is disclosed. The matchbox oven includes a housing, a slider, a mover and a heat source. The housing includes a cavity having a first and second openings. The mover moves the slider in and out of the cavity through the first and second openings. The heat source provides heat to the cavity for heating up any food item placed on a portion of the slider located within the cavity. The slider, which is configured to receive food items, includes multiple stoppers to serve as oven covers for preventing heat within the cavity from escaping through the first and second openings. When necessary, a portion of the slider can also be utilized as a heat sink for lowering the temperature of the cavity during oven operation.

RELATED PATENT APPLICATIONS

This patent application is a divisional of U.S. application Ser. No.13/236,695 filed on Sep. 20, 2011.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to ovens in general, and in particular toa matchbox oven capable of providing continuous food cooking whileminimizing heat loss.

2. Description of Related Art

A conveyor oven typically has a first opening through which uncookedfood enters and a second opening at the opposite end of the oven throughwhich cooked food exits. A stainless steel conveyor belt is commonlyused to carry food items through a heated cavity between the first andsecond openings. The conveyor belt extends past both openingssufficiently to allow safe insertion and retrieval of food items. Thisarrangement allows food items to be placed on the conveyor belt on acontinuous basis to achieve sequential steady-state cooking.

When food items offered by a commercial foodservice operation such as arestaurant are to be cooked at the same heat transfer profile for thesame amount of time, a conveyor oven is particularly advantageous. Afoodservice personnel needs only set the temperature, blower speed andconveyor belt speed as necessary to cook the selected foods. After theabove-mentioned three parameters have been set, the conveyor oven can beoperated continuously without any further adjustments. As such, even aperson unskilled in the art of cooking is able to prepare high-qualitycooked food products simply by placing them on the conveyor belt of aconveyor oven. The ease of operation and high throughput make conveyorovens highly desirable in restaurants and other commercial foodservicesettings.

However, conveyor ovens also have their disadvantages. For example, mostcommercial foodservice operations offer a variety of food items, such aspizza, chicken, vegetables and pies. Even a single food order at arestaurant may include multiple types of food items. Conveyor ovens arevery efficient when cooking similar food items, but not so for cooking avariety of food items that require vastly different cooking times andheat transfer profiles. In addition, conveyer ovens are not very energyefficient because the two openings allow tremendous heat loss duringtheir operation, and the lost heat must be replaced in order to maintaina steady cooking temperature. Furthermore, the heat that escapes fromconveyor ovens must be extracted, typically via an air conditioningsystem, so that the ambient temperature of the kitchen area in which theconveyor ovens reside does not increase beyond an uncomfortable levelfor foodservice personnel. All of the above adds to the cost offoodservice operations when using conveyor ovens.

Consequently, it would be desirable to provide a flexible oven that isenergy-efficient as well as operationally efficient.

SUMMARY OF THE INVENTION

In accordance with one embodiment of the present invention, a matchboxoven includes a housing, a slider, a mover and a heat source. Thehousing includes a cavity having a first and second openings The movermoves the slider in and out of the cavity through the first and secondopenings. The heat source provides heat to the cavity for heating up anyfood item placed on a portion of the slider located within the cavity.The slider, which is configured to receive food items, includes multiplestoppers to serve as oven covers for preventing heat within the cavityfrom escaping through the first and second openings. When necessary, aportion of the slider can also be utilized as a heat sink for loweringthe temperature of the cavity during oven operation.

All features and advantages of the present invention will becomeapparent in the following detailed written description.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention itself, as well as a preferred mode of use, furtherobjects, and advantages thereof, will best be understood by reference tothe following detailed description of an illustrative embodiment whenread in conjunction with the accompanying drawings, wherein:

FIG. 1 is a front view of a matchbox oven, in accordance with oneembodiment of the present invention;

FIG. 2 is a cross-sectional view of a cavity within the matchbox ovenfrom FIG. 1;

FIG. 3 is a diagram of a heating and airflow system within the matchboxoven from FIG. 1;

FIGS. 4 a-4 c are a top view and side views of the slider within thematchbox oven from FIG. 1;

FIGS. 5 a-5 c illustrate a method of cooking when only one of foodloading sections of the matchbox oven from FIG. 1 is being used; and

FIGS. 6 a-6 f illustrate a method of cooking when both food loadingsections of the matchbox oven from FIG. 1 are being used.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings and in particular to FIG. 1, there isdepicted a front view of a matchbox oven, in accordance with oneembodiment of the present invention. As shown, a matchbox oven 10 isdefined by a housing 11 having a cavity 12. Housing 11, as well ascavity 12, has a first opening 18 and a second opening 19. Matchbox oven10 includes a heating and airflow system (not shown) to supply heat tocavity 12 for heating up any food items that have been carried intocavity 12 through either first opening 18 or second opening 19 via aslider 20.

Matchbox oven 10 also includes a first control panel 15 and a secondcontrol panel 16. An operator can enter operating parameters, such ascooking temperature, cooking time, blower speed, etc., via first andsecond control panels 15, 16 to effectuate cooking controls on any fooditems placed within cavity 12. First and second control panels 15, 16are preferably implemented with touchscreens but they can also beimplemented with keypads and liquid crystal displays (LCDs).

With reference now to FIG. 2, there is depicted a cross-sectional viewof the housing 11, that accommodates slider 20 having a first foodloading section 21 and a second food loading section 22. The surfaces offirst and second food loading sections 21, 22 are substantially planar.First and second food loading sections 21, 22 are configured to receivecooking plates 27, 28, respectively. Any food item intended to be cookedby matchbox oven 10 is initially placed on either one of cooking plates27, 28. Cooking plates 27, 28 can be identical or different from eachother, depending on the types of food items to be prepared. Thus,cooking plate 27 may be made of a different material and/or a differentdesign from cooking plate 28.

Preferably, operating parameters for matchbox oven 10 to cook any fooditems placed on food loading section 21 to be carried into cavity 12through first opening 18 can be entered at first control panel 15 (fromFIG. 1). Similarly, operating parameters for matchbox oven 10 to cookany food items placed on food loading section 22 to be carried intocavity 12 through second opening 19 can be entered at second controlpanel 16 (from FIG. 1).

When food loading section 21 is located inside cavity 12 where food isbeing cooked, food loading section 22 is located outside housing 11where it is being cooled by the ambient air of a kitchen in whichmatchbox oven 10 resides. Similarly, when food loading section 22 islocated inside cavity 12 where food is being cooked, food loadingsection 21 is located outside housing 11 where it is being cooled by theambient air of the kitchen in which matchbox over 10 resides. Due to thelarge temperature differential between the cooled food loading section21 (or food loading section 22) and cavity 12, food loading section 21(or food loading section 22) can be sent into cavity 12 to rapidly bringdown the temperature of cavity 12, when necessary, after food loadingsection 21 (or food loading section 22) has been sufficiently cooleddown by the ambient air. In essence, the air-cooled food loading section21 (or food loading section 22) serves as a heat sink for absorbing theheat within cavity 12. From a time-saving standpoint, this maneuver isparticularly advantageous in getting matchbox oven 10 ready for cookinga food item that requires a lower cooking temperature than the currenttemperature of cavity 12. This is because it takes less time to raisethe temperature of cavity 12 up to the desired temperature by theheating and airflow system (after the cavity's current temperature hasbeen lowered by one of food loading sections 21-22) than to lower thecavity's current temperature down to the desired temperature by allowingheat to escape from cavity 12.

Slider 20 also includes a first stopper 23, a second stopper 24 and athird stopper 25. Third stopper 25 serves as a divider between first andsecond food loading sections 21, 22 as well as an oven cover to preventheat within cavity 12 from escaping through openings 18, 19. Along withthird stopper 25, first and second stoppers 23, 24 serve as oven coversto prevent heat within cavity 12 from escaping through openings 18, 19,depending on the placement of slider 20 in relation to cavity 12. Forexample, first and third stoppers 23, 25 can serve as oven covers forfirst and second openings 18, 19, respectively. Similarly, third andsecond stoppers 25, 24 can serve as oven covers for first and secondopenings 18, 19, respectively.

Slider 20 is connected to a stepper motor (not shown) that powers thelinear movement of slider 20 in and out of cavity 12. Although slider 20is moved by a stepper motor, it is understood by those skilled in theart that slider 20 can also be moved manually via a lever system or by avariety of other motorized movement designs.

In addition, housing 11 also contains a top plenum 35 and a bottomplenum 38. Top plenum 35 is connected to a top nozzle plate 34. Bottomplenum 38 is connected to a bottom nozzle plate 37. Top nozzle plate 34,top plenum 35, bottom nozzle plate 37 and bottom plenum 38 are part ofthe heating and airflow system for matchbox oven 10 such that heated airin top plenum 35 and bottom plenum 38 are in gaseous communication withcavity 12 through top nozzle plate 34 and bottom nozzle plate 37,respectively. Top nozzle plate 34 and bottom nozzle plate 37 includemultiple conical shape nozzles for directing hot pressured airstreamtowards any food items placed on the portion of slider 20 located withincavity 12. Although air passes through top nozzle plate 34 and bottomnozzle plate 37 into cavity 12, it is understood by those skilled in theart that top plenum 35 or bottom plenum 38 could be in gaseouscommunication with cavity 12 via a variety of air opening configurationssuch as tubes, rectangular openings and the like. Moreover, air canenter cavity 12 through only one of top plenum 35 or bottom plenum 38.

For additional heating, an optional infrared radiation heating element36 can be placed within cavity 12 somewhere between slider 20 and bottomnozzle plate 37 or between slider 20 and top nozzle plate 34 forsupplying heat towards any food located on first loading section 21 orsecond loading section 22 of slider 20. It is understood by thoseskilled in the art that other heating elements, such as microwave, steamor a combination thereof, can be used instead of infrared radiationheating element 36.

Referring now to FIG. 3, there is depicted a diagram of the heating andairflow system within matchbox oven 10. Air within cavity 12 isinitially pumped in to a heater plenum 31 via an intake opening 30.Heater plenum 31 includes a heater 39. After it has been sufficientlyheated by heater 39, the hot air is then directed to top plenum 35 via atop blower 32 and to bottom plenum 38 via a bottom blower 33. Thepressurized hot air formed within top plenum 35 is subsequently directedto cavity 12 via multiple nozzles located on top nozzle plate 34 (fromFIG. 2). Similarly, pressurized hot air formed within bottom plenum 38is subsequently directed to cavity 12 via multiple nozzles located onbottom nozzle plate 37 (from FIG. 2). Although heated air is shown to besent to top plenum 35 and bottom plenum 38 via separate blowers, it isunderstood by those skilled in the art that heated air can be sent toboth top plenum 35 and bottom plenum 38 via a single blower.

FIG. 4 a depicts a top view of slider 20. As shown, slider 20, whichincludes first and second food loading sections 21-22 and stoppers23-25, is supported by a first pair of rails 42, 43 and a second pair ofrails 44, 45. The linear movement of slider 20 on top of rails 42, 43 ispreferably powered by a stepper motor 41. The widths of stoppers 23-25,which may be the same, are wider than the thickness of openings 18, 19.Thus, two of stoppers 23-25 can serve as oven covers to prevent heatwithin cavity 12 from escaping through openings 18, 19, depending on theplacement of slider 20 in relation to cavity 12. Although three stoppers23-25 are shown in the illustrated embodiment, it is possible to employless than three stoppers on slider 20 at the expense of a higher heatloss from cavity 12.

FIGS. 4 b-4 c depict two side views of slider 20 for the presentembodiment of the present invention. In FIG. 4 b, first food loadingsection 21 is shown to be located within cavity 12, with first and thirdstoppers 23, 25 positioned centrally within first and second openings18, 19, respectively. In this position, first and third stoppers 23, 25serve as oven covers for first and second openings 18, 19, respectively.In FIG. 4 c, second food loading section 22 is shown to be locatedwithin cavity 12, with third and second stoppers 25, 24 positionedcentrally within first and second openings 18, 19, respectively. In thisposition, third and second stoppers 25, 24 serve as oven covers forfirst and second openings 18, 19, respectively.

In FIGS. 4 b-4 c, stoppers 23-25 are shown to be positioned centrallywithin openings 18-19. However, during a cooking cycle, slider 20 can bemoved to-and-fro slightly and repeatedly to allow the edges of two ofstoppers 23-25 to flush with openings 18-19 of housing 11. Suchmovements are designed to avoid overheating of a food item at any spotlocated directly underneath a nozzle. The distance within which slider20 can be moved to-and-fro is preferably dictated by the widths ofstoppers 23-25 in order to avoid heat loss from cavity 12 during suchmovements.

Referring now to FIGS. 5 a-5 c, there are illustrated a method ofcooking when only one of food loading sections 21, 22 of slider 20 isused, in accordance with the exemplary embodiment of the presentinvention. An uncooked raw food item (RF) is initially placed on foodloading section 22 (or 21), as shown in FIG. 5 a. An operator thenenters an appropriate cook settings for cooking the food item viacontrol panel 16 (or 15), and food loading section 22 (or 21) issubsequently moved within cavity 12, as depicted in FIG. 5 b. After aperiod of time has lapsed, food loading section 22 (or 21) exits cavity12, and the fully cooked food item (CF) is ready to be removed from foodloading section 22 (or 21) by an operator, as shown in FIG. 5 c.

With reference now to FIGS. 6 a-6 f, there are illustrated a method ofcooking when both food loading sections 21, 22 of slider 20 are beingused, in accordance with the exemplary embodiment of the presentinvention. A first uncooked raw food item (RF-1) is initially placed onfood loading section 22, and an operator then enters an appropriate cooksetting for cooking the first food item via control panel 16, as shownin FIG. 6 a. Food loading section 22 is subsequently moved inside cavity12, as depicted in FIG. 6 b. While the first food item is being cooked(F-1-C), a second uncooked raw food item (RF-2) can be placed on foodloading section 21, and the operator enters an appropriate cook settingsfor cooking the second food item via control panel 15, as depicted inFIG. 6 c. After a period of time has lapsed, food loading section 22 onwhich the first food item is fully cooked (CF-1) exits cavity 12 whilefood loading section 21 is moved inside cavity 12, as shown in FIG. 6 d.While the second food item is being cooked (F-2-C), the fully cookedfirst food item (CF-1) is ready to be removed by the operator from foodloading section 22, as shown in FIG. 6 e.

While the second food item is being cooked (F-2-C), a third uncooked rawfood item (RF-3) can be placed on food loading section 22, and theoperator enters an appropriate cook settings for cooking the third fooditem via control panel 16, as depicted in FIG. 6 f.

The above-mentioned sequence can be performed repeatedly for differentfood items. Since different cooking times can be entered by afoodservice personnel, any of the above-mentioned food items can becompletely different from each other.

In addition, an interrupt mode can be added to matchbox oven 10. Forcertain food items, a foodservice personnel may require to interrupt thenormal cooking cycle by entering a cook temperature that is less thanthe preset cook temperature of matchbox oven 10. If the newly enteredcook temperature is within approximately 20% less than the preset cooktemperature of matchbox oven 10, the process of cooling the cavity'stemperature can be accelerated by using one of food loading sections 21,22 that has been cooled by ambient air of a kitchen as a heat sink tolower the temperature of cavity 12. For much of the duration of the cookcycle, the preset temperature of matchbox oven 10 at which thetemperature feedback loop operates is temporarily lowered to the newtemperature entered by the foodservice personnel. Once the cook cycle isnear completion, the preset temperature of matchbox oven 10 reverts backto the original preset temperature so that the next cooking cycle willnot start from an unacceptably low starting temperature.

As has been described, the present invention provides a matchbox ovenfor continuously and efficiently cooking a wider variety of food itemswhile minimizing heat loss, resulting in improved energy efficiency.

While the invention has been particularly shown and described withreference to an exemplary embodiment, it will be understood by thoseskilled in the art that various changes in form and detail may be madetherein without departing from the spirit and scope of the invention.

1. An oven comprising: a housing having a cavity and first and secondopenings; a slider comprising a first section that linearly moves a fooditem into the cavity through the first opening and a second section thatlinearly moves another food item into the cavity through the secondopening, wherein one of the first and second sections is located outsideof the cavity when the other one of the first and second sections islocated within the cavity, and wherein the one of the first and secondsections located outside the cavity is configured to be moved into thecavity to serve as a heat sink for absorbing the heat within the cavity;and a heat source for providing heat to the cavity for heating up anyfood item placed within the cavity, a control panel arrangement forapplying a first cook setting to the oven when the first section of theslider is within the cavity, and for applying a second cook setting tothe oven when the second section of the slider is within the cavity,wherein the first cook setting and the second cook setting areindependent of each other.
 2. The oven of claim 1, wherein the slidermoves only linearly.
 3. The oven of claim 1, wherein the control panelarrangement comprises a first control panel for entering the first cooksetting; and a second control panel for entering the second cooksetting.
 4. The oven of claim 1, further comprising a plurality ofstoppers, wherein two of the plurality of stoppers prevent heat fromescaping from the cavity through the first and second openings when oneof the first and second sections is located within the cavity.
 5. Theoven of claim 4, wherein one of the plurality of stoppers comprises adivider between the first and second sections.
 6. The oven of claim 4,wherein the slider is configured to move to-and-fro within the width ofone of the plurality of stoppers while a food item is heating up withinthe cavity.
 7. The oven of claim 1, further comprising a moveroperatively connected to the slider to linearly move the slider in andout of the cavity through the first and second openings.
 8. The oven ofclaim 17, further comprising a mover operatively connected to the sliderto move the slider bidirectionally, wherein a food item placed on thefirst section is moved in and out of the cavity through the firstopening and a food item placed on the second section is moved in and outof the cavity through the second opening.
 9. An oven comprising: ahousing having a cavity and first and second openings; a surface that isonly linearly movable, wherein a food item placed on a first portion ofthe surface is moved into the cavity through the first opening andanother food item placed on a second portion of the surface is movedinto the cavity through the second opening; a heat source for providingheat to the cavity for heating up any food item placed on one of thefirst and second portions of the surface located within the cavity; anda control panel arrangement for applying a first cook temperaturesetting to the oven when the first portion of the surface is within thecavity and for applying a second cook temperature setting to the ovenwhen the second portion of the surface is within the cavity, whereinwhen applying one of the first and second cook settings that has a lowertemperature than the temperature in the cavity, one of the first andsecond portions that is located outside the cavity is moved into thecavity to serve as a heat sink absorbing the heat within the cavitythereby lowering the temperature within the cavity.
 10. The oven ofclaim 9, further comprising a plurality of stoppers mounted on thesurface, wherein o of the plurality of stoppers close the first andsecond openings thereby inhibiting heat from escaping from the cavitythrough the first and second openings when one of the first and secondportions of the surface is located within the cavity.
 11. The oven ofclaim 10, wherein the surface is configured to move to-and-fro withinthe width of one of the plurality of stoppers while a food item beingheated within the cavity.
 12. The oven of claim 9, further comprising amover operatively connected to the surface to linearly move the surfacein and out of the cavity through the first and second openings.
 13. Theoven of claim 12, wherein the mover comprises a stepper motor.
 14. Theoven of claim 9, wherein the control panel arrangement comprises: afirst control panel for entering the first cook setting; and a secondcontrol panel for entering the second cook setting.
 15. The oven ofclaim 9, wherein: the first portion of the surface comprises a firstfood loading section; and the second portion of the surface comprises asecond food loading section.
 16. The oven of claim 9, further comprisinga mover operatively connected to linearly move the surfacebidirectionally, wherein a first food item placed on the first portionof the surface is moved in and out of the cavity through the firstopening and a second food item placed on the second portion of thesurface is moved in and out of the cavity through the second opening.